Archimica Inc. - Executive Summary |
|
Archimica Inc. is a multi-purpose batch chemical manufacturing facility located in Elgin, South Carolina. The facility is situated in the southern sector of approximately 200 acres of contiguous land. Surrounding property is rural residential/farmland. Archimica Inc. utilizes four (4) RMP regulated chemicals: allyl alcohol; bromine; chlorine; and hydrogen chloride. Allyl alcohol is stored on site in a maximum quantity of approximately 165,000 pounds, bromine is stored on site in a maximum quantity of approximately 250,000 pounds, chlorine is stored on site in a maximum quantity of approximately 60,000 pounds, and hydrogen chloride (anhydrous) is stored on site in a maximum quantity of approximately 25,000 pounds. Materials that may evolve hydrochloric acid were also evaluated as hydrogen chloride for the purposes of worst case and alternative release scenarios. For each of these chemicals measures have been taken to prevent and/or mitigate potential for accidental releases. Effo rts for each chemical are detailed below. Allyl alcohol is used in several processes. A maximum on-site quantity is approximately 165,000 pounds. For each of these processes the same bulk storage and transfer facilities are utilized. Allyl alcohol is stored in two (2) diked 5000-gallon storage tanks. The storage tanks are equipped with level indicators, and vent to a regenerative thermal oxidizer. Overfill protection is provided by piping the tank vents to a knockout pot, with level, temperature, and pressure indicators. This knockout pot also vents to the regenerative thermal oxidizer. These tanks are filled from tanker trucks which are staged on an adjacent concreted area surrounded by trenches. These trenches discharge to an in-ground sump, equipped with a metal cover and vented to the regenerative thermal oxidizer through a detonation arrestor. If a full tank truck or the unloading hose were to fail, the contents of the tank truck would spill on the unloading area. The spill would be contained by trenches that discharge into the in-ground sump described above. The in-ground sump has a volume of 54,000 gallons, and is pumped to a plant-wide wastewater collection system that feeds a biological treatment system owned by Archimica. The trenches are basically 18" deep and 12" wide. Sections of the trenches may be isolated in the event of a spill or leak. Reactor systems for allyl alcohol use are all similar in design and use. Each reactor system consists of a stainless steel reactor, two stainless steel receivers, and associated stainless steel tanks and piping. Failure of a reactor or receiver will result in the released allyl alcohol being collected in the surrounding trenches. These releases would have much less impact than the tank truck or unloading piping failure detailed above. Recovered allyl alcohol is stored in several of the stainless steel storage tanks associated with the allyl alcohol processes. These tanks contain from 480 pounds to 7432 pounds. This is considerably less than the 35,862 pounds in the AA-1 and AA-2 storage tanks or the full tanker truck. The worst case scenario for toxics is detailed in the seciton on chlorine. The alternative release scenario resulting in the farthest distance to a toxic endpoint for allyl alcohol is failure of a reactor containing a full batch charge. This results in a distance to endpoint of 0.32 miles. Bromine is also used in several processes at Archimica, and has a total storage capacity of approximately 250,000 pounds. All bromine storage tanks, receivers, and pumps are housed in two containment buildings. These vessels are also diked inside the buildings, and are equipped with deluge systems for the dikes in the event of a catastrophic release. Both bromine buildings are vented to emergency scrubbers. In the event of a storage vessel failure and containment of the bromine in a dike, the bromine sensors will immediately activate the emergency scrubbers and evac uate the vapor space of the building. The scrubbers can be activated manually or automatically by bromine/chlorine sensors located inside the containment buildings. Bromine off-gases from manufacturing processes are vented through acid absorbers and caustic scrubbers. Bromine is stored in three (3) 5000-gallon lead-lined storage tanks, designed with a pressure rating of 50 psig. Bromine is weighed on a batch basis for individual processes into three (3) 500-gallon glass-lined receivers. All bromine tanks and receivers are diked and housed in containment buildings. Measures are in place to prevent accidental releases from the bromine tanks and receivers. All storage tanks and receivers are equipped with rupture discs and relief valves. A corrosion resistant rupture disc is installed just above the vessel shell. Above this rupture disc is a pressure relief valve. In the event that overpressurization bursts the rupture disc, the relief valve would control the release by allow th e overpressure to relieve to the point of the rating of the relief valve only. This would minimize the amount of bromine released to the building. The rupture disc protects the relief valve from corrosion until operational. A pressure indicator is installed between the rupture disc and the relief valve for detection of rupture disc failure. Bromine is received on-site in tank trailers and off-loaded into one of the three (3) storage tanks via pressure. The tank truck is parked inside the containment building while unloading. All connections are bolted flanges, and all transfer lines are teflon-lined steel construction. Material handler personnel are present during the entire unloading operation. The worst case scenario for toxics is presented in the section on chlorine. The alternative release scenario which resulted in the farthest distance to a toxic endpoint for bromine is failure of transfer piping. This results in a distance to endpoint of 1.02 miles. Chlorine is curren tly used in three (3) processes at Archimica Inc. It is received and used in one-ton cylinders only. Cylinders are stored and used inside specially constructed containment buildings equipped with chlorine sensors for leak detection. Each chlorine building is equipped with an emergency scrubber capable of evacuating the contents of a one-ton cylinder within 45 minutes. Chlorine is vaporized in the buildings and transferred to production equipment as a vapor, which minimizes the quantity of chlorine in the piping. Piping outside the containment buildings is enclosed in corrosion resistant piping ductwork. This ductwork directs any piping leakage back to the containment buildings where sensors will detect the leak and activate the emergency scrubber(s). The ductwork is easily opened to allow for piping inspection and repair. As an administrative control, no more than one chlorine cylinder is open to the plant manifold at any one time. Chlorine addition is typically interlocked to batch reactor agitation and temperature alarms to prevent transfer when these parameters are out of spec. The worst case scenario for chlorine (and for all toxics) is failure of a one-ton cylinder. This results in a distance to toxic endpoint of 2.09 miles. The alternative release scenario for chlorine is failure of transfer piping. This results in a distance to endpoint of 1.26 miles. Hydrogen chloride is received and used at Archimica as anhydrous hydrogen chloride in one (1) process at Archimica Inc. Hydrogen chloride (as hydrochoric acid) can potentially be released from the use and/or release of several raw materials on-site. The potential releases from the anhydrous hydrogen chloride and the hydrochloric acid evolution from raw materials were evaluated for worst case and alternative release scenarios. Anhydrous hydrogen chloride is received in a specially designed tube trailer containing approximately 25,000 pounds. This trailer is parked inside a specially designed c ontainment building while the contents are being transferred into the process(es) using it as a raw material. The containment building is equipped with an emergency scrubber. The containment building is designed to contain all hydrogen chloride released from a tube failure, and the emergency scrubber will be manually activated to remove the gas from the building. The tube trailer consists of seven (7) individual tubes containing approximately 3000 pounds each. A rupture disc on the tube trailer is set to release at 2700-3000 psig. A fusable metal plug will melt at 158-175 F. An excess flow valve is installed in the discharge system to limit the flow to a maximum of 800 pounds per hour. A pressure regulator reduces the source pressure to 20 psig. Double check valves eliminate back-flow potential. The delivery system for anhydrous hydrogen chloride is rated for 1500 psig. All hydrogen chloride piping is enclosed in corrosion resistant piping ductwork. This ductwork will direct any piping leakage back to the containment building where the emergency scrubber will evacuate and scrub the hydrogen chloride vapors. Another potential source of hydrogen chloride release is the release/spillage of anhydrous aluminum chloride. This material is received in 5000-pound fiberglass bins (with steel framing), transferred to fiberglass lined steel weigh hoppers mounted on load cells. The bins are positioned above the weigh hoppers by a manually operated, electric hoist system. All reactions involving anhydrous aluminum chloride are conducted in glass-lined reactor systems equipped with caustic scrubbers. Aluminum chloride bins are inspected each time before hoisting. The glass-lined reactors are inspected twice per month (one manual glass inspection using spark device - one conductive solution test). Aluminum chloride evolves hydrogen chloride (hydrochloric acid) only in the presence of water. To reduce the potential of such a release an administrative control h as been put in place: aluminum chloride bins will not be transported by forklift during a rain event. The aluminum chloride hoist systems are installed inside sontainment areas to prevent contact with rainfall. Humidity does not yield significant hydrochloric acid releases. Thionyl chloride is another raw material which has the potential to release hydrogen chloride (hydrochloric acid) from contact with water. Thionyl chloride is received and stored in drums. The thionyl chloride receiver is located inside a containment building. In the event of a spill or release only humidity will contribute to the evolution of hydrochloric acid. All piping for this raw material is enclosed in corrosion resistant piping ductwork as detailed above for chlorine and hydrogen chloride. The worst case scenario for toxics was defined above for chlorine. The alternative release scenario for hydrogen chloride which resulted in the farthest distance to the endpoint was failure of transfer piping. Th is resulted in a distance to endpoint of 1.43 miles. Archimica Inc. has a well-organized, highly trained emergency response group (Fire Brigade) which is the first line of defense in response to any release. Certified firefighters, haz-mat responders, Emergency Medical Technicians (EMTs) are all a part of this group. Archimica Inc. also has coordinated agreements with the local LEPC, which consists of local and county fire departments, nearby industry response personnel, hospitals, law enforcement and government personnel. Archimica Inc. is well prepared for response to any of the potential releases detailed in this Plan, and others. In summary, four (4) specially designed containment buildings have been constructed to reduce the likelihood and the severity of potential releases. Each building is equipped with a deluge system and an emergency scrubber to evacuate and treat the vapor space of these buildings in the event of a release. Bromine and chlorine sensors have been instal led in the bromine and chlorine buildings and in the appropriate plant areas for leak detection. All chlorine, hydrogen chloride, and thionyl chloride piping is enclosed in corrosion resistant piping ductwork. Aluminum chloride is not transported about the facility during rain events, and the hoist system is equipped with a containment system to prevent contact with water. Archimica Inc. also has a very detailed and active mechanical integrity program for inspection and maintenance of piping, tanks, reactors, and equipment. This program is a valuable tool for prevention and minimization of releases. |